RFC: An "API" for overriding array values in config data

Weird title - sorry. Let me explain...

The module ~~Config::Loader~~ Config::Merge has the ability to override the default config with local values. For instance, on your development machine, you may want to use a different database host. So you can override just that value:


   app:
     servers:
        db:
          host:     db.domain.com
          username: username
          password: password
        email:
          host:     mail.domain.com
          etc
[download]

Then override/merge with:

      app:
        servers:
          db:
             host:  dev.domain.com
          email:
             host:  dev.domain.com
[download]

A deep merge of hashes is done, so that the other config data is preserved.

I would like to provide a mechanism for altering arrays, rather than just having to copy and paste the entire array. So what I have thought of is the following:


    main:
        cronjobs:
           - job1
           - job2
           - job3
           - job4
           - job5
[download]

Then override/merge with:

    main:
      cronjobs:
         '!' :                        # key '!' must exist to signal m
+erge
             '-' :                    # delete elements 3 and 5
                 - 3
                 - 5
             '+' :                    # append jobs 6 and 7
                 - job6
                 - job7
          OR 
             '+' :                    # insert job8 at index 2, job9 a
+t index 5
                 2: job8
                 5: job9

         1:  job10                    # change index1 from job2 to job
+10
[download]

I realise that most people probably won't use this, but I have wanted something like this on occasion, and so I was wondering if anybody had a better/simpler way of representing these changes?

thanks

Clint

UPDATE - corrected hostname to host (thanks fenLisesi)

UPDATE - change the module name to Config::Merge

Comment on RFC: An "API" for overriding array values in config data Select or Download Code

Replies are listed 'Best First'.
Re: RFC: An "API" for overriding array values in config data by princepawn (Parson) on Jun 19, 2007 at 13:42 UTC
The more complications I see with config files and modules, the more persuaded I am by Uri Guttman's statement that Perl modules work just fine for configuring his apps. Carter's compass: I know I'm on the right track when by deleting something, I'm adding functionality	[reply]
Re^2: RFC: An "API" for overriding array values in config data by clinton (Priest) on Jun 19, 2007 at 13:45 UTC
Sure - and I'm torn between adding this or not, for that very reason. I think I WILL add it (under "Advanced Usage Only") because (a) I have wanted to use something like this in the past, and (b) you don't have to use it if you don't want to. thanks for the comment Clint	[reply]


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